Rock-drill.



controlling devices as is generally the case.

WILLIAM CHARLES STEPHENS, or oonNwALL, ENGLAND,

nocK-DnILL.

Specification of Letters -Patent.

Patented Dec. 28,1909.

Application ined August 1, 190s. serial 110.446,450.

To all rwhom it may concer/n:

Be it known ,that I, WVILLIAM .CHARLES- STEPHENS, a subject of the Kingof Great Britain, residing` at Garn Brea, Cornwall, England, haveinvented new and useful Impro'vements' lin -or Connected with Rock-Drills,vof which the followingis a specification.

This invention relates to rock drills of the kind where.water is usedfor allaying the dust formed by' drilling andhas for its` object theprovision of meanswhereby the supply of motive Huid for operating thedrill and the supply of. water can be simultaneously controlled insteadof using separate A further object is to provide against leakage wherethe drill bit enters its holder and to arrange for the easy extractionof the bit from the said holder.

According to the invention I rovide a I tap or valve which is formedwith inlets and that when the said part ismoved the motive fluid andwater will both be turnedpn or oit'.V In practice I so varrange therecesses that the water' is lturned on before the motive fluid in lorderto linsure the free flow of water before the drilling takes place. Toprevent4 water leaking around the drill shank within the holder Iprovide a conical- To enable my'invention to be Afully under-- stood Iwill describe the same by reference to the accompanying drawing, inwhich Figure 1 isa longitudinal sectional elevation of a percussive'rock drill ofthe kind having an automatic air-feed as described in thespecification of my application Serial blo-446,449 of even date herewithand provided with-my improvements. Fig. 21s a plan, and Fig 3 asectional side elevation thereof. Fig. 4 is an elevation ofthe front iend thereof. Fig. 5 is a section on the'line 5-.-5, Fig. 4. Fig. 6 is asection on the 1ine- 6-, Fig. 2 and Figs. AII and 8 are respectivelysections on the lines 7-7 and 8 8, Fig. 6. Fig. 9 is a similar View toFig, 8

- 'showing a different position .of the parts.

a tool for removingthe drill bit from its holder. f

a is the main cylinder or hammer cylinder of the drill, b the pistonthereof, and c the valve forcontrolling the supply ofmotive fluid to thesaid piston from the passage 01. thereof, d2 being the supply porttherefor. e is the drill holder or bolster against which 'the hammer 'boperates and which carries and forms the support for thel hollow drillbit f and g is the central hole -in the bolster into which the water tosupply the bit flows from the holes la., lz, in communication with therecess z' containing the grooved and perforated ring j. Allof Ithe said.parts were described in the said specification of even date herewith. Y

7c is the tap or cock for controlling the supply of' pressure Huid tothe main iston :and feed piston and of water to the dr1ll bitf. This taphas inlets Z and m for the supply of the pressure fluid and waterrespectively. The plug ln. of the cock is formed with recesses o, p, therecess o being desi ed to connect the inlet Z with the port w ich isformed in one with the ports o1 an d2 for supplying the main and feedcylinders while the recess p is designed to bring the inlet m intocommunication with the passage 0' to the drill-bit The recess p is soarranged relatively wlth t-he recess o that when the plug a is turnedslightly, when-starting the drill, the water supply is -iirst effected,the 'water passing to the cutting edges of the bit before the drilllcommences to work and thus insuring the free flow of water takin placebefore striking the rock to be drilled so that cut portions of rock are,prevented from choking the hole in the bit. By further rotation of the.plug ln, the .pressure fluid is then admitted to the cylinders aand dand the drill then commences to operate the water being full on. Ialso-provide a screw valve or regulator s in the inlet m so that thesupply can be diminished.

t' is the conical hole whichv I provide in vthe holder or bolster e andu is thecorrespondingly shaped shank-on the bit-'fvhich 'when jammedback into'the hole #maires a iii-the ba f iid w,

d is the feed'cyhnder and d1 the piston,

wedge which Figs. 10 and 11 are views at right angles of the drillshank'. By a simple'tapwitha hammer the Wedgeforces the' collar awayfrom the drill holder and so extracts the drill bit.

Although I have describedv my improvements in connection, with-a drillof the percussive type it will `be obvious that they can .be employedwith other types of employing Water tofallay dust While: drilling.

Having now particularly described and ascertained the nature of my saidinvention4 and in what manner same is to be performed,

I declare that what I claim is In a rockdrill, the combination with the4drill cylinder and iston, and a drill ybit holder provided Witl meansfor supplyin Waterfto the drill bit, ofa controlling coc casing providedwith a Water inlet, a 'motive let operatively connected with the'cylinder nfor supplying motive fluid thereto, of a single cock in saidcasing provided With a passage for connecting the motive fluid in-A etand outlet, and a passage for connecting the water inlet and outlet,having a p0rtion ada ted to be brought into operativeposition 1n advanceof the' motive iiuid' assage, whereby Water is admitted to the rill bitbeforelthe Vvdrill is brought into operation, substantially as describWILLIAM CHARLES STLBHENS.

. Witnesses: Y HOWARD Fox, W. H. DANIELL.-

